Aggregation Expression - $concatArrays

Function Build

Build $concatArrays with the ConcatArrays function from the aggregation package.

// bson.D{bson.E{Key:"allTags", Value:bson.D{bson.E{Key:"$concatArrays", Value:[]interface {}{"$tags", "$extraTags"}}}}}
result := aggregation.ConcatArrays("allTags", "$tags", "$extraTags")

Method Build (Builder)

Build $concatArrays with the ConcatArrays method from aggregation.NewBuilder().

// bson.D{bson.E{Key:"allTags", Value:bson.D{bson.E{Key:"$concatArrays", Value:[]interface {}{"$tags", "$extraTags"}}}}}
result := aggregation.NewBuilder().
    ConcatArrays("allTags", "$tags", "$extraTags").
    Build()

Build Without Key

When an expression needs to be passed as an argument to another expression, use a WithoutKey variant to build an expression fragment without an output field name.

ConcatArraysWithoutKey

Function build:

// bson.D{bson.E{Key:"$concatArrays", Value:[]any{"$tags", "$extraTags"}}}
expr := aggregation.ConcatArraysWithoutKey("$tags", "$extraTags")

Method build (Builder):

// bson.D{bson.E{Key:"$concatArrays", Value:[]any{"$tags", "$extraTags"}}}
expr := aggregation.NewBuilder().
    ConcatArraysWithoutKey("$tags", "$extraTags").
    Build()